wp postmeta with a lot of enfold orginal data

Hello
We are using wp 4.8 ,enfold latest, woocommerce latest

our wp postmeta is getting huge recently, so we check in php admin and found out The default theme demo are still in the there
how we can we delete by some SQL?

BDW, are all the images and alt text and prices,product tags been stored the wp post meta?

if yes, there are a lot of database trashed, how can we delete them in database?

and if run below SQL, will it delete all the details from woocommerce singe product page(such as price,product tag, thumbnails, iamges?)

DELETE FROM wp_postmeta WHERE meta_key = ‘_wp_attached_file’;

DELETE FROM wp_postmeta WHERE meta_key = ‘_wp_attachment_metadata’;